Question
- State the condition under which a large magnification can be achieved in an astronomical telescope.
- Give two reasons to explain why a reflecting telescope is preferred over a refracting telescope.
✓
Answer
- $m=-\frac{f_0}{f_e}$
By increasing 𝑓0 / decreasing 𝑓𝑒
- No chromatic aberration.
- No spherical aberration.
- Mechanical advantage – low weight, easier to support.
- Mirrors are easy to prepare.
- More economical.
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